@heikkim Hello, to enable wifi you should enable the interface in /boot/boot.cmd by commenting the followin lines (add a # at the beginning)
fdt set /soc/mmc@01c10000/bcrmf@1 status "disabled"
fdt set /soc/mmc@01c10000 status "disabled"
Then run mkimage -C none -A arm -T script -d /boot/boot.cmd /boot/boot.scr and reboot.
Does it work?

@ntd said in Internal ModBUS problem:
I will update this thread when I will have some news.
Well, I installed the new SD card a couple of months ago and received no complaints ever since, so I suppose this update solved the problem.
@Martin-Kudláček: thanks again for your support .